[Federal Register Volume 64, Number 194 (Thursday, October 7, 1999)]
[Proposed Rules]
[Pages 54596-54598]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 99-26213]


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DEPARTMENT OF TRANSPORTATION

Federal Aviation Administration

14 CFR Part 39

[Docket No. 98-ANE-48-AD]
RIN 2120-AA64


Airworthiness Directives; Pratt & Whitney JT8D Series Turbofan 
Engines

AGENCY: Federal Aviation Administration, DOT.

ACTION: Notice of proposed rulemaking (NPRM).

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SUMMARY: This document proposes the supersedure of an existing 
airworthiness directive (AD), applicable to certain Pratt & Whitney 
JT8D series turbofan engines, that currently requires revisions to the 
Time Limits Section (TLS) of the JT8D Turbofan Engine Manuals to 
include required enhanced inspection of selected critical life-limited 
parts at each piece-part exposure. This action would add additional 
critical life-limited parts for enhanced inspection. This proposal is 
prompted by additional focused inspection procedures that have been 
developed by the manufacturer. The actions specified by this proposed 
AD are intended to prevent critical life-limited rotating engine part 
failure, which could result in an uncontained engine failure and damage 
to the airplane.

DATES: Comments must be received by December 6, 1999.

ADDRESSES: Submit comments to the Federal Aviation Administration 
(FAA), New England Region, Office of the Regional Counsel, Attention: 
Rules Docket No. 98-ANE-48-AD, 12 New England Executive Park, 
Burlington, MA 01803-5299. Comments may also be sent via the Internet 
using the following address: ``[email protected]''. Comments sent 
via the Internet must contain the docket number in the subject line. 
Comments may be inspected at this location between 8:00 a.m. and 4:30 
p.m., Monday through Friday, except Federal holidays.

FOR FURTHER INFORMATION CONTACT: Christopher Spinney, Aerospace 
Engineer, Engine Certification Office, FAA, Engine and Propeller 
Directorate, 12 New England Executive Park, Burlington, MA 01803-5299; 
telephone (781) 238-7175, fax (781) 238-7199

SUPPLEMENTARY INFORMATION:

Comments Invited

    Interested persons are invited to participate in the making of the 
proposed rule by submitting such written data, views, or arguments as 
they may desire. Communications should identify the Rules Docket number 
and be submitted to the address specified above. All communications 
received on or before the closing date for comments, specified above, 
will be considered before taking action on the proposed rule. The 
proposals contained in this notice may be changed in light of the 
comments received.
    Comments are specifically invited on the overall regulatory, 
economic, environmental, and energy aspects of the proposed rule. All 
comments submitted will be available, both before and after the closing 
date for comments, in the Rules Docket for examination by interested 
persons. A report summarizing each FAA-public contact concerned with 
the substance of this proposal will be filed in the Rules Docket.
    Commenters wishing the FAA to acknowledge receipt of their comments 
submitted in response to this notice must submit a self-addressed, 
stamped postcard on which the following statement is made: ``Comments 
to Docket Number 98-ANE-48-AD.'' The postcard will be date stamped and 
returned to the commenter.

Availability of NPRMs

    Any person may obtain a copy of this NPRM by submitting a request 
to the FAA, New England Region, Office of the Regional Counsel, 
Attention: Rules Docket No. 98-ANE-48-AD, 12 New England Executive 
Park, Burlington, MA 01803-5299.

Discussion

    On June 1, 1999, the Federal Aviation Administration (FAA) issued 
airworthiness directive (AD) 99-12-03, Amendment 39-11187 (64 FR 30379, 
June 8, 1999), to require revisions to the Time Limits Section (TLS) of 
the Pratt & Whitney (PW) JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, 
-15, -15A, -17, -17A, -17R, and -17AR series Turbofan Engine Manuals to 
include required enhanced inspection of selected critical

[[Page 54597]]

life-limited parts at each piece-part exposure. That AD was prompted by 
a Federal Aviation Administration (FAA) study of in-service events 
involving uncontained failures of critical rotating engine parts that 
indicated the need for improved inspections. That condition, if not 
corrected, could result in critical life-limited rotating engine part 
failure, which could result in an uncontained engine failure and damage 
to the airplane.

New Inspection Procedures

    Since the issuance of that AD, PW has developed additional focused 
inspection procedures. This proposal would add first stage high 
pressure (HP) turbine disks and shafts that would require enhanced 
inspection at each piece-part exposure.

Proposed Actions

    Since an unsafe condition has been identified that is likely to 
exist or develop on other products of this same type design, the 
proposed AD would supersede AD 99-12-03 to add additional critical 
life-limited parts for enhanced inspection at each piece-part 
opportunity.

Economic Analysis

    The FAA estimates that 5,821 engines installed on airplanes of U.S. 
registry would be affected by this proposed AD, that it would take 
approximately 8 work hours per engine to perform the enhanced 
inspection for the first stage HP turbine disks and shafts. The average 
labor rate is $60 per work hour. The cost impact of the added 
inspections per engine is approximately $480 per year, with the 
approximate total cost for the U.S. fleet of $2,794,080 per year.

Regulatory Impact

    The regulations proposed herein would not have substantial direct 
effects on the States, on the relationship between the national 
government and the States, or on the distribution of power and 
responsibilities among the various levels of government. Therefore, in 
accordance with Executive Order 12612, it is determined that this 
proposal would not have sufficient federalism implications to warrant 
the preparation of a Federalism Assessment.
    For the reasons discussed above, I certify that this proposed 
regulation (1) Is not a ``significant regulatory action'' under 
Executive Order 12866; (2) is not a ``significant rule'' under the DOT 
Regulatory Policies and Procedures (44 FR 11034, February 26, 1979); 
and (3) if promulgated, will not have a significant economic impact, 
positive or negative, on a substantial number of small entities under 
the criteria of the Regulatory Flexibility Act. A copy of the draft 
regulatory evaluation prepared for this action is contained in the 
Rules Docket. A copy of it may be obtained by contacting the Rules 
Docket at the location provided under the caption ADDRESSES.

List of Subjects in 14 CFR Part 39

    Air transportation, Aircraft, Aviation safety, Safety.

The Proposed Amendment

    Accordingly, pursuant to the authority delegated to me by the 
Administrator, the Federal Aviation Administration proposes to amend 
part 39 of the Federal Aviation Regulations (14 CFR part 39) as 
follows:

PART 39--AIRWORTHINESS DIRECTIVES

    1. The authority citation for part 39 continues to read as follows:

    Authority: 49 U.S.C. 106(g), 40113, 44701.


Sec. 39.13  [Amended]

    2. Section 39.13 is amended by removing Amendment 39-11187 (64 FR 
30379, June 8, 1999), and by adding a new airworthiness directive, to 
read as follows:

Pratt & Whitney: Docket No. 98-ANE-48-AD. Supersedes AD 99-12-03, 
Amendment 39-11187.

    Applicability: Pratt & Whitney (PW) JT8D-1, -1A, -1B, -7, -7A, -
7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR series 
turbofan engines, installed on but not limited to Boeing 727 and 737 
series, and McDonnell Douglas DC-9 series airplanes.

    Note 1: This airworthiness directive (AD) applies to each engine 
identified in the preceding applicability provision, regardless of 
whether it has been modified, altered, or repaired in the area 
subject to the requirements of this AD. For engines that have been 
modified, altered, or repaired so that the performance of the 
requirements of this AD is affected, the owner/operator must request 
approval for an alternative method of compliance in accordance with 
paragraph (c) of this AD. The request should include an assessment 
of the effect of the modification, alteration, or repair on the 
unsafe condition addressed by this AD; and, if the unsafe condition 
has not been eliminated, the request should include specific 
proposed actions to address it.

    Compliance: Required as indicated, unless accomplished 
previously.
    To prevent critical life-limited rotating engine part failure, 
which could result in an uncontained engine failure and damage to 
the airplane, accomplish the following:

Inspections

    (a) Within the next 30 days after the effective date of this AD, 
revise the Time Limits Section (TLS) of the JT8D-1, -1A, -1B, -7, -
7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, and -17AR series 
Turbofan Engine Manuals, and for air carrier operations revise the 
approved continuous airworthiness maintenance program, by adding the 
following:

``Critical Life Limited Part Inspection

A. Inspection Requirements

    (1) This section has the definitions for individual engine 
piece-parts and the inspection procedures which are necessary when 
these parts are removed from the engine.
    (2) It is necessary to do the inspection procedures of the 
piece-parts in Paragraph B when:
    (a) The part is removed from the engine and disassembled to the 
level specified in paragraph B and
    (b) The part has accumulated more than 100 cycles since the last 
piece part inspection, provided that the part is not damaged or 
related to the cause of its removal from the engine.
    (3) The inspections specified in this section do not replace or 
make unnecessary other recommended inspections for these parts or 
other parts.

B. Parts Requiring Inspection

    Note: Piece part is defined as any of the listed parts with all 
the blades removed.

                              Engine Manual
------------------------------------------------------------------------
            Description                Section          Inspection
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                    Hub (Disk), 1st Stage Compressor
------------------------------------------------------------------------
491201.............................     72-33-31  -02, -03, -04
496501.............................     72-33-31  -02, -03, -04
504101.............................     72-33-31  -02, -03, -04
515201.............................     72-33-31  -02, -03, -04
594301.............................     72-33-31  -02, -03, -04
640501.............................     72-33-31  -02, -03, -04
640601.............................     72-33-31  -02, -03, -04
743301.............................     72-33-31  -02, -03, -04
749701.............................     72-33-31  -02, -03, -04
749801.............................     72-33-31  -02, -03, -04
750001.............................     72-33-31  -02, -03, -04
750101.............................     72-33-31  -02, -03, -04
778901.............................     72-33-31  -02, -03, -04
791401.............................     72-33-31  -02, -03, -04
791501.............................     72-33-31  -02, -03, -04
791601.............................     72-33-31  -02, -03, -04
791701.............................     72-33-31  -02, -03, -04
791801.............................     72-33-31  -02, -03, -04
806001.............................     72-33-31  -02, -03, -04
806101.............................     72-33-31  -02, -03, -04
817401.............................     72-33-31  -02, -03, -04
844401.............................     72-33-31  -02, -03, -04
845401.............................     72-33-31  -02, -03, -04
848001.............................     72-33-31  -02, -03, -04
848101.............................     72-33-31  -02, -03, -04
------------------------------------------------------------------------
                       Disk, 2nd Stage Compressor
------------------------------------------------------------------------
482502.............................     72-33-33  -02
502502.............................     72-33-33  -02
520602.............................     72-33-33  -02
570302.............................     72-33-33  -02
570402.............................     72-33-33  -02
678202.............................     72-33-33  -02
730202.............................     72-33-33  -02
730302.............................     72-33-33  -02

[[Page 54598]]

 
730402.............................     72-33-33  -02
740502.............................     72-33-33  -02
745702.............................     72-33-33  -02
745902.............................     72-33-33  -02
746002.............................     72-33-33  -02
746802.............................     72-33-33  -02
760402.............................     72-33-33  -02
760502.............................     72-33-33  -02
807502.............................     72-33-33  -02
500240201..........................     72-33-33  -02
790832 (Disk assembly).............     72-33-33  -02
------------------------------------------------------------------------
              Turbine Disk, First Stage With Integral Shaft
------------------------------------------------------------------------
481135.............................     72-52-04  -03
494211.............................     72-52-04  -03
500701.............................     72-52-04  -03
516101.............................     72-52-04  -03
529115.............................     72-52-04  -03
538901.............................     72-52-04  -03
544501.............................     72-52-04  -03
544601.............................     72-52-04  -03
544701.............................     72-52-04  -03
553201.............................     72-52-04  -03
558401.............................     72-52-04  -03
565101.............................     72-52-04  -03
565201.............................     72-52-04  -03
565301.............................     72-52-04  -03
578201.............................     72-52-04  -03
579001.............................     72-52-04  -03
------------------------------------------------------------------------
                 HP Turbine Disk, First Stage, Separable
------------------------------------------------------------------------
587501.............................     72-52-02  -03
5006101-01.........................     72-52-02  -03
578001.............................     72-52-02  -03
5005201-01.........................     72-52-02  -03
696801.............................     72-52-02  -03
742501.............................     72-52-02  -03
752401.............................     72-52-02  -03
767601.............................     72-52-02  -03
792801.............................     72-52-02  -03
856501.............................     72-52-02  -03
832201.............................     72-52-02  -03
855701.............................     72-52-02  -03
856401.............................     72-52-02  -03
5003601-01.........................     72-52-02  -03
5003601-021........................     72-52-02  -03
5004301-01.........................     72-52-02  -03''
------------------------------------------------------------------------

    (b) Except as provided in paragraph (c) of this AD, and 
notwithstanding contrary provisions in section 43.16 of the Federal 
Aviation Regulations (14 CFR 43.16), these mandatory inspections 
shall be performed only in accordance with the TLS of the PW JT8D-1, 
-1A, -1B, -7, -7A, -7B, -9, -9A, -11, -15, -15A, -17, -17A, -17R, 
and -17AR series Turbofan Engine Manuals.

Alternative Methods of Compliance

    (c) An alternative method of compliance or adjustment of the 
compliance time that provides an acceptable level of safety may be 
used if approved by the Engine Certification Office (ECO). Operators 
shall submit their requests through an appropriate FAA Principal 
Maintenance Inspector (PMI), who may add comments and then send it 
to the ECO.

    Note 2: Information concerning the existence of approved 
alternative methods of compliance with this airworthiness directive, 
if any, may be obtained from the ECO.

Ferry Flights

    (d) Special flight permits may be issued in accordance with 
sections 21.197 and 21.199 of the Federal Aviation Regulations (14 
CFR 21.197 and 21.199) to operate the airplane to a location where 
the requirements of this AD can be accomplished.

Continuous Airworthiness Maintenance Program

    (e) FAA-certificated air carriers that have an approved 
continuous airworthiness maintenance program in accordance with the 
record keeping requirement of Sec. 121.369(c) of the Federal 
Aviation Regulations (14 CFR 121.369(c)) of this chapter must 
maintain records of the mandatory inspections that result from 
revising the TLS of the PW JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, 
-11, -15, -15A, -17, -17A, -17R, and -17AR series Turbofan Engine 
Manuals, and the air carrier's continuous airworthiness program. 
Alternately, certificated air carriers may establish an approved 
system of record retention that provides a method for preservation 
and retrieval of the maintenance records that include the 
inspections resulting from this AD, and include the policy and 
procedures for implementing this alternate method in the air 
carrier's maintenance manual required by Sec. 121.369(c) of the 
Federal Aviation Regulations (14 CFR 121.369(c)); however, the 
alternate system must be accepted by the appropriate PMI and require 
the maintenance records be maintained either indefinitely or until 
the work is repeated. Records of the piece-part inspections are not 
required under Sec. 121.380(a)(2)(vi) of the Federal Aviation 
Regulations (14 CFR 121.380(a)(2)(vi)). All other operators must 
maintain the records of mandatory inspections required by the 
applicable regulations governing their operations.

    Note 3: The requirements of this AD have been met when the 
engine manual changes are made and air carriers have modified their 
continuous airworthiness maintenance plans to reflect the 
requirements in the PW JT8D-1, -1A, -1B, -7, -7A, -7B, -9, -9A, -11, 
-15, -15A, -17, -17A, -17R, and -17AR series Turbofan Engine 
Manuals.

    Issued in Burlington, Massachusetts, on September 30, 1999.
David A. Downey,
Assistant Manager, Engine and Propeller Directorate, Aircraft 
Certification Service.
[FR Doc. 99-26213 Filed 10-6-99; 8:45 am]
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